In the design of heating units for residential and commercial use, it has been common practice to provide a heat exchange unit, such as a radiator, containing liquid and with an electrical heater. The advantage of such units is that they can be placed easily in almost any location with a minimum amount of plumbing installation and can be simply plugged into an electrical convenience outlet. This is true, irrespective of whether the installation is to be permanent or temporary. The difficulty with such heating units, however, is that they are very inefficient. The heat available at the heat-exchange portion is the heat that can be absored by the metal in the radiator from the liquid inside. The metal receives this heat by conduction from the liquid, but only in an amount commenserate with lowering the temperature of the liquid as it flows through the radiator. Circulation takes place usually by the thermo-syphonic principle. With a given amount of heat capacity, therefore, the radiator must be quite large. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a heating unit with a large heating capacity despite its small size.
Another object of the invention is the provision of a heating unit which can be readily changed from one location to another and installed with no plumbing installation and with only a simple electrical connection.
A further object of the present invention is the provision of a heating unit making use of the heat of vaporization in its operation.
It is another object of the instant invention to provide a heating unit which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.